Effect of acidic solution and immersion duration on the corrosion behaviour of the aluminium 6061 alloy

Abstract

The current investigation's goal is to examine the corrosion effect of aluminium 6061 alloys. The acidic immersion corrosion experiment was utilised to perform the corrosion test. The experiments were carried out in accordance with the L9 orthogonal array tables with two corrosion parameters: acidic solution and immersion duration with three levels. Taguchi’s methodology optimised the corrosion parameters to obtain a minimum corrosion rate on aluminium 6061 alloys. The results reveal that the chloride ions cause huge corrosion in the aluminium alloy samples dipped in a hydrochloric acidic solution. Meanwhile, significant possible corrosion happened in the initial stage of immersion of samples in the acidic solution. This is due to the termination of a protective aluminium oxide layer over the circumference area of the aluminium alloy. Moreover, the Taguchi technique revealed minor corrosion in the aluminium samples dipped in a nitric acidic solution (HNO3) for 216 h. Analysis of Variance (ANOVA) confirmed the contribution of two corrosion parameters on the corrosion rate of the aluminium alloy. The Scanning Electron Microscope (SEM) shows the presence of chloride traces over the surface of the highly corroded aluminium alloy.